Spillage of fuel is both wasteful and a significant source of pollution and is perhaps one of the major environmental problems impacting the oceans and waterways of the world. The problem is particularly severe in a marine environment, since spilled fuel can also be a fire or explosion hazard, as well as a direct source of pollution and waste. Fuel spillage can occur during refueling of a vehicle as a result of overfilling or fuel surging back up a filler neck as a result of inadequate ventilation or erratic pressure in the refueling line. Fuel spillage also can occur during the use of a vehicle as a result of fuel splashing up through a fuel tank vent or through an improperly closed fuel filler port. A number of venting and valving systems have been proposed in the prior art; however, these systems often rely upon the use of pressure responsive valves, complex fuel channels and the like. An example of a fuel retention fuel tank is shown in EP 761487. As a result, such systems are expensive, prone to failure, and often difficult to retrofit onto an existing vehicle.
The present invention is directed to a fuel filling and venting system which is simple in design and highly reliable. The system of the present invention is relatively low in cost, and may be readily installed into existing vehicles. The system of the present invention permits continuous venting of a fuel tank, while preventing back venting and surging of fuel during filling or use of the vehicle.
In other embodiments of the present invention, there is provided a fueling system having a sensor which is operative to automatically shut off a fuel pump when the fuel tank is full.